Abstract

Background

Nipah virus (NiV) is a highly pathogenic zoonotic agent in the family Paramyxoviridae that is maintained in nature by bats. Outbreaks have occurred in Malaysia, Singapore,
India, and Bangladesh and have been associated with 40 to 75% case fatality rates.
There are currently no vaccines or postexposure treatments licensed for combating
human NiV infection.

Methods and results

Four groups of ferrets received a single vaccination with different recombinant vesicular
stomatitis virus vectors expressing: Group 1, control with no glycoprotein; Group
2, the NiV fusion protein (F); Group 3, the NiV attachment protein (G); and Group
4, a combination of the NiV F and G proteins. Animals were challenged intranasally
with NiV 28 days after vaccination. Control ferrets in Group 1 showed characteristic
clinical signs of NiV disease including respiratory distress, neurological disorders,
viral load in blood and tissues, and gross lesions and antigen in target tissues;
all animals in this group succumbed to infection by day 8. Importantly, all specifically
vaccinated ferrets in Groups 2-4 showed no evidence of clinical illness and survived
challenged. All animals in these groups developed anti-NiV F and/or G IgG and neutralizing
antibody titers. While NiV RNA was detected in blood at day 6 post challenge in animals
from Groups 2-4, the levels were orders of magnitude lower than animals from control
Group 1.

Conclusions

These data show protective efficacy against NiV in a relevant model of human infection.
Further development of this technology has the potential to yield effective single
injection vaccines for NiV infection.